Optical lens system

ABSTRACT

The present invention provides an optical lens system comprising, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a fourth lens element; and a fifth lens element having a concave image-side surface, the object-side and image-side surfaces thereof being aspheric and at least one inflection point being formed on the image-side surface. Such arrangement of optical elements can effectively minimize the size of the optical lens system, lower the sensitivity of the optical system, and obtain higher image resolution.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a)on Taiwanese Patent Application No(s). 099133981 filed in Taiwan,R.O.C., on Oct. 6, 2010, the entire contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical lens system, and moreparticularly, to a compact optical lens system used in a portableelectronic product.

2. Description of the Prior Art

In recent years, due to the popularity of portable electronic productswith photographing functions, the demand for a compact imaging lenssystem is increasing, and the sensor of a general photographing camerais none other than CCD (Charge-coupled Device) or CMOS device(Complementary Metal-oxide-semiconductor Device). Furthermore, asadvances in semiconductor manufacturing technology have allowed thepixel size of sensors to be reduced, and the resolution of a compactimaging lens system has gradually increased, there is an increasingdemand for a compact imaging lens system featuring better image quality.

A conventional compact imaging lens system used in a portable electronicproduct generally comprises four lens elements, such as the onedisclosed in U.S. Pat. No. 7,365,920. However, as smartphones, PDAs orother high-end mobile devices are gaining popularity, the demand for acompact imaging lens system which features even more pixels and evenbetter image quality is also rising. A conventional lens systemcomprising four lens elements became insufficient for high-end imagingmodules; meanwhile, electronic products are becoming more and morepowerful yet featuring a compact design. Therefore, there is anincreasing demand for an optical lens system which can be used inportable, compact electronic products with higher image quality whilehaving a moderate total track length.

Therefore, a need exists in the art for an optical lens system featuringa simple manufacturing process and better image quality.

SUMMARY OF THE INVENTION

The present invention provides an optical lens system comprising, inorder from an object side to an image side: a first lens element withpositive refractive power having a convex object-side surface; a secondlens element with negative refractive power; a third lens element withpositive refractive power having a convex object-side surface and aconvex image-side surface; a fourth lens element; and a fifth lenselement having a concave image-side surface, the object-side andimage-side surfaces thereof being aspheric and at least one inflectionpoint being formed on the image-side surface, wherein the optical lenssystem is further provided with a stop disposed between an object andthe third lens element, and an electronic sensor disposed at an imageplane for the image formation of the object; a focal length of theoptical lens system is f; a focal length of the third lens element isf3; a distance on an optical axis between the stop and the electronicsensor is SL; a distance on the optical axis between the object-sidesurface of the first lens element and the electronic sensor is TTL; andthey satisfy the following relations: 0.00<f/f3<1.90, and0.7<SL/TTL<1.2.

Moreover, the present invention provides an optical lens systemcomprising, in order from an object side to an image side: a first lenselement with positive refractive power having a convex object-sidesurface; a second lens element with negative refractive power; a thirdlens element with positive refractive power having a convex object-sidesurface and a convex image-side surface; a fourth lens element withpositive refractive power; and a fifth lens element with negativerefractive power having a concave image-side surface, both of theobject-side and image-side surfaces thereof being aspheric and at leastone inflection point being formed on the image-side surface, wherein theoptical lens system is further provided with a stop disposed between anobject and the third lens element, and an electronic sensor disposed atan image plane for the image formation of the object; a focal length ofthe optical lens system is f; a focal length of the first lens elementis f1; a distance on an optical axis between the stop and the electronicsensor is SL; a distance on the optical axis between the object-sidesurface of the first lens element and the electronic sensor is TTL; andthey satisfy the following relations: 1.00<f/f1<2.30, and0.7<SL/TTL<1.2.

Such arrangement of optical elements can effectively minimize the sizeof the optical lens system, lower the sensitivity of the optical system,and obtain higher image resolution.

In an optical lens system of the present invention, the first lenselement with positive refractive power provides the positive refractivepower of the optical lens system; this allows the total track length ofthe optical lens system to be favorably reduced. The second lens elementhas negative refractive power; this allows aberrations produced by thefirst lens element, as well as chromatic aberrations of the optical lenssystem, to be effectively corrected. The third lens element withpositive refractive power effectively distributes the refractive powerof the first lens element, thereby reducing the sensitivity of theoptical lens system. The fourth lens element and the fifth lens elementmay have positive or negative refractive power. When the fourth lenselement has positive and the fifth lens element has negative refractivepower, they will form a telephoto structure with one positive and onenegative refractive power. This allows the back focal length of theoptical lens system to be favorably reduced, thereby reducing the totaltrack length.

In an optical lens system of the present invention, the first lenselement may be a bi-convex lens element or a meniscus lens elementhaving a convex object-side surface and a concave image-side surface.When the first lens element is a bi-convex lens element, the refractivepower of the first lens element can be effectively distributed, therebyreducing the total track length of the optical lens system. When thefirst lens element is a meniscus lens element, the astigmatism of theoptical lens system can be favorably corrected. The second lens elementhas a concave object-side surface; this allows the back focal length ofthe optical lens system to be extended favorably, so that there will besufficient space to accommodate other components in the optical lenssystem. Preferably, the second lens element has a concave object-sidesurface and a concave image-side surface; this allows the Petzval sum ofthe optical lens system to be effectively corrected, and moreover, theback focal length of the optical lens system can be extended favorablyto have sufficient space for accommodating other components in theoptical lens system. The third lens element has a convex object-sidesurface and a convex image-side surface; this enhances the positiverefractive power of the third lens element so that the refractive powerof the first lens element can be effectively distributed, therebyreducing the total track length and lowering the sensitivity of theoptical lens system. The fourth lens element may have a concaveobject-side surface and a convex image-side surface; this allows theastigmatism of the optical lens system to be corrected favorably. Thefifth lens element has a concave image-side surface; this allows theprincipal point of the optical lens system to be placed away from theimage plane, thereby reducing the total track length favorably andminimizing the optical lens system.

In an optical lens system of the present invention, the stop may bedisposed between the object and the first lens element, between thefirst lens element and the second lens element, or between the secondlens element and the third lens element. With the first lens elementproviding positive refractive power and by placing the stop close to theobject, the total track length of the optical lens system can beeffectively reduced. The aforementioned arrangement also enables theexit pupil of the optical lens system to be positioned far away from theimage plane; thus, light will be projected onto the electronic sensor ata nearly perpendicular angle, and this is the telecentric feature of theimage side. The telecentric feature is very important to thephotosensitive ability of the current solid-state sensor because it canimprove the photosensitivity of the sensor to reduce the probability ofshading occurrences. In addition, the image-side surface of the fifthlens element can be provided with an inflection point; as a result, theangle at which light is projected onto the sensor from the off-axisfield can be effectively reduced, thereby further correcting theoff-axis aberrations. Moreover, when the stop is disposed closer to thethird lens element, a wide field of view can be favorably achieved. Sucharrangement of the stop can facilitate the correction of distortions andchromatic aberrations of magnification, as well as reduce thesensitivity of the optical lens system effectively.

Therefore, in an optical lens system of the present invention, the stopis disposed between the object and the third lens element for thepurpose of achieving a good balance between the telecentric feature anda wide field of view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an optical lens system in accordance with a firstembodiment of the present invention.

FIG. 1B shows the aberration curves of the first embodiment of thepresent invention.

FIG. 2A shows an optical lens system in accordance with a secondembodiment of the present invention.

FIG. 2B shows the aberration curves of the second embodiment of thepresent invention.

FIG. 3A shows an optical lens system in accordance with a thirdembodiment of the present invention.

FIG. 3B shows the aberration curves of the third embodiment of thepresent invention.

FIG. 4A shows an optical lens system in accordance with a fourthembodiment of the present invention.

FIG. 4B shows the aberration curves of the fourth embodiment of thepresent invention.

FIG. 5A shows an optical lens system in accordance with a fifthembodiment of the present invention.

FIG. 5B shows the aberration curves of the fifth embodiment of thepresent invention.

FIG. 6A shows an optical lens system in accordance with a sixthembodiment of the present invention.

FIG. 6B shows the aberration curves of the sixth embodiment of thepresent invention.

FIG. 7A shows an optical lens system in accordance with a seventhembodiment of the present invention.

FIG. 7B shows the aberration curves of the seventh embodiment of thepresent invention.

FIG. 8 is TABLE 1 which lists the optical data of the first embodiment.

FIG. 9 is TABLE 2 which lists the aspheric surface data of the firstembodiment.

FIG. 10 is TABLE 3 which lists the optical data of the secondembodiment.

FIG. 11 is TABLE 4 which lists the aspheric surface data of the secondembodiment.

FIG. 12 is TABLE 5 which lists the optical data of the third embodiment.

FIG. 13 is TABLE 6 which lists the aspheric surface data of the thirdembodiment.

FIG. 14 is TABLE 7 which lists the optical data of the fourthembodiment.

FIG. 15 is TABLE 8 which lists the aspheric surface data of the fourthembodiment.

FIG. 16 is TABLE 9 which lists the optical data of the fifth embodiment.

FIG. 17 is TABLE 10 which lists the aspheric surface data of the fifthembodiment.

FIG. 18 is TABLE 11 which lists the optical data of the sixthembodiment.

FIG. 19 is TABLE 12 which lists the aspheric surface data of the sixthembodiment.

FIG. 20 is TABLE 13 which lists the optical data of the seventhembodiment.

FIG. 21 is TABLE 14 which lists the aspheric surface data of the seventhembodiment.

FIG. 22 is TABLE 15 which lists the data of the respective embodimentsresulting from the equations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides an optical lens system comprising, inorder from an object side to an image side: a first lens element withpositive refractive power having a convex object-side surface; a secondlens element with negative refractive power; a third lens element withpositive refractive power having a convex object-side surface and aconvex image-side surface; a fourth lens element; and a fifth lenselement having a concave image-side surface, the object-side andimage-side surfaces thereof being aspheric and at least one inflectionpoint being formed on the image-side surface. The optical lens system isfurther provided with a stop disposed between an object and the thirdlens element, and an electronic sensor disposed at an image plane forthe image formation of the object; a focal length of the optical lenssystem is f; a focal length of the third lens element is f3; a distanceon an optical axis between the stop and the electronic sensor is SL; adistance on the optical axis between the object-side surface of thefirst lens element and the electronic sensor is TTL; and they satisfythe following relations: 0.00<f/f3<1.90, and 0.7<SL/TTL<1.2.

When the relation of 0.00<f/f3<1.90 is satisfied, the refractive powerof the third lens element is more appropriate, and the positiverefractive power of the first lens element can be effectivelydistributed, thereby reducing the sensitivity of the optical lenssystem. Preferably, the following relation is satisfied: 0.00<f/f3<0.80.

When the relation of 0.7<SL/TTL<1.2 is satisfied, a good balance betweenthe telecentric feature and a wide field of view of the optical lenssystem can be favorably achieved.

In the aforementioned optical lens system, preferably, the fourth lenselement has a concave object-side surface and a convex image-sidesurface; this allows the astigmatism of the optical lens system to befavorably corrected. Preferably, at least one of the object-side andimage-side surfaces of the fourth lens element is aspheric, which cancorrect different types of aberrations within the optical lens system.Furthermore, the fifth lens element is made of plastic which can reducethe total weight and cost of the optical lens system.

In the aforementioned optical lens system, preferably, the second lenselement has a concave image-side surface; this allows the back focallength of the optical lens system to be extended favorably, so thatthere will be sufficient space to accommodate other components in theoptical lens system. Preferably, the second lens element has a concaveobject-side surface; this allows the Petzval sum of the optical lenssystem to be effectively corrected, and moreover, the back focal lengthof the optical lens system can be extended favorably to have sufficientspace for accommodating other components in the optical lens system.

In the aforementioned optical lens system, the focal length of theoptical lens system is f, a focal length of the first lens element isf1, and preferably, they satisfy the following relation: 1.00<f/f1<2.30.When this relation is satisfied, the refractive power of the first lenselement can be distributed in a more balanced manner; this allows thetotal track length of the optical lens system to be effectivelycontrolled and prevents high order spherical aberrations from increasingexcessively while improving image quality of the optical lens system.Preferably, the following relation is satisfied: 1.30<f/f1<2.00.

In the aforementioned optical lens system, an Abbe number of the firstlens element is V1, an Abbe number of the second lens element is V2, andpreferably, they satisfy the following relation: 28.0<V1−V2<42.0. Whenthis relation is satisfied, chromatic aberrations of the optical lenssystem can be favorably corrected.

In the aforementioned optical lens system, an Abbe number of the secondlens element is V2, an Abbe number of the third lens element is V3, andpreferably, they satisfy the following relation: |V2−V3|<12.0. When thisrelation is satisfied, the optical lens system's ability to correctchromatic aberrations can be favorably improved.

In the aforementioned optical lens system, a thickness of the secondlens element on the optical axis is CT2, the focal length of the opticallens system is f, and preferably, they satisfy the following relation:0.02<CT2/f<0.15. When this relation is satisfied, the thickness of thesecond lens element is more favorable. As a result, higher manufacturingefficiency can be obtained during the lens production process, and theyield rate can be improved; also, the lens elements can be formed moreeasily with a higher homogeneity.

In the aforementioned optical lens system, a radius of curvature of theobject-side surface of the first lens element is R1, a radius ofcurvature of the image-side surface of the first lens element is R2, andpreferably, they satisfy the following relation: −0.80<R1/R2<0.50. Whenthis relation is satisfied, spherical aberrations of the optical lenssystem can be favorably corrected; moreover, the first lens element canhelp reducing the total track length of the optical lens system, therebyallowing the system to be effectively minimized.

In the aforementioned optical lens system, a radius of curvature of theobject-side surface of the fifth lens element is R9, a radius ofcurvature of the image-side surface of the fifth lens element is R10,and they satisfy the following relation: |R10/R9|<1.3. When thisrelation is satisfied, the principal point of the optical lens systemcan be placed away from the image plane, thereby reducing the totaltrack length favorably and minimizing the optical lens system.Preferably, the following relation is satisfied, |R10/R9|<0.8.

In the aforementioned optical lens system, the focal length of theoptical lens system is f, the focal length of the third lens element isf3, a focal length of the fourth lens element is f4, a focal length ofthe fifth lens element is f5, and preferably, they satisfy the followingrelation: |(f/f3)+(f/f4)+(f/f5)|<0.5. When this relation is satisfied,the refractive power of the third, fourth and fifth lens elements can bedistributed in a more balanced manner, thereby reducing the sensitivityand aberrations of the optical lens system favorably.

In the aforementioned optical lens system, the distance on the opticalaxis between the stop and the electronic sensor is SL, the distance onthe optical axis between the object-side surface of the first lenselement and the electronic sensor is TTL, and preferably, they satisfythe following relation: 0.8<SL/TTL<0.98. When this relation issatisfied, a good balance between the telecentric feature and a widefield of view of the optical lens system can be favorably achieved.

In the aforementioned optical lens system, the distance on the opticalaxis between the object-side surface of the first lens element and theelectronic sensor is TTL, half of a diagonal length of an effectivepixel area of the electronic sensor is ImgH, and preferably, theysatisfy the following relation: TTL/ImgH<2.10. When this relation issatisfied, the optical lens system can maintain a compact size which isfavorable for the installation into a compact electronic product.

Moreover, the present invention provides an optical lens systemcomprising, in order from an object side to an image side: a first lenselement with positive refractive power having a convex object-sidesurface; a second lens element with negative refractive power; a thirdlens element with positive refractive power having a convex object-sidesurface and a convex image-side surface; a fourth lens element withpositive refractive power; and a fifth lens element with negativerefractive power having a concave image-side surface, both of theobject-side and image-side surfaces thereof being aspheric and at leastone inflection point being formed on the image-side surface. The opticallens system is further provided with a stop disposed between an objectand the third lens element, and an electronic sensor disposed at animage plane for the image formation of the object; a focal length of theoptical lens system is f; a focal length of the first lens element isf1; a distance on an optical axis between the stop and the electronicsensor is SL; a distance on the optical axis between the object-sidesurface of the first lens element and the electronic sensor is TTL; andthey satisfy the following relations: 1.00<f/f1<2.30, and0.7<SL/TTL<1.2.

When the relation of 1.00<f/f1<2.30 is satisfied, the total track lengthof the optical lens system can be effectively controlled; also,excessive increase of high order spherical aberrations can be avoided,thereby improving image quality of the optical lens system. Preferably,the following relation is satisfied: 1.30<f/f1<2.00.

When the relation of 0.7<SL/TTL<1.2 is satisfied, a good balance betweenthe telecentric feature and a wide field of view of the optical lenssystem can be favorably achieved.

In the aforementioned optical lens system, preferably, the second lenselement has a concave object-side surface and a concave image-sidesurface; this allows the Petzval sum of the optical lens system to beeffectively corrected, and moreover, the back focal length of theoptical lens system can be extended favorably to have sufficient spacefor accommodating other components in the optical lens system.

In the aforementioned optical lens system, preferably, the fourth lenselement has a concave image-side surface and a convex image-sidesurface; this allows the astigmatism of the optical lens system to befavorably corrected. Preferably, at least one of the object-side andimage-side surfaces of the fourth lens element is aspheric, and thefifth lens element is made of plastic.

In the aforementioned optical lens system, the focal length of theoptical lens system is f, a focal length of the third lens element isf3, and preferably, they satisfy the following relation: 0.00<f/f3<0.80.When this relation is satisfied, the refractive power of the third lenselement is more appropriate, and the positive refractive power of thefirst lens element can be effectively distributed, thereby reducing thesensitivity of the optical lens system.

In the aforementioned optical lens system, an Abbe number of the firstlens element is V1, an Abbe number of the second lens element is V2, andpreferably, they satisfy the following relation: 28.0<V1−V2<42.0. Whenthis relation is satisfied, chromatic aberrations of the optical lenssystem can be favorably corrected.

In the aforementioned optical lens system, a focal length of the fourthlens element is f4, a focal length of the fifth lens element is f5, andpreferably, they satisfy the following relation: 0.4<|f4/f5|<1.6. Whenthis relation is satisfied, the refractive power of the fourth and fifthlens elements can be distributed in a more balanced manner, therebycorrecting high order aberrations effectively and improving theresolution of the optical lens system.

In the aforementioned optical lens system, the focal length of theoptical lens system is f, the focal length of the third lens element isf3, the focal length of the fourth lens element is f4, the focal lengthof the fifth lens element is f5, and preferably, they satisfy thefollowing relation: |(f/f3)+(f/f4)+(f/f5)|<0.5. When this relation issatisfied, the refractive power of the third, fourth and fifth lenselements can be distributed in a more balanced manner, thereby reducingthe sensitivity and aberrations of the optical lens system favorably.

In the aforementioned optical lens system, the distance on the opticalaxis between the stop and the electronic sensor is SL, the distance onthe optical axis between the object-side surface of the first lenselement and the electronic sensor is TTL, and preferably, they satisfythe following relation: 0.8<SL/TTL<0.98. When this relation issatisfied, a good balance between the telecentric feature and a widefield of view of the optical lens system can be favorably achieved.

In the aforementioned optical lens system, a radius of curvature of theobject-side surface of the fifth lens element is R9, a radius ofcurvature of the image-side surface of the fifth lens element is R10,and preferably, they satisfy the following relation: |R10/R9|<0.8. Whenthis relation is satisfied, the principal point of the optical lenssystem can be placed away from the image plane, thereby reducing thetotal track length favorably and minimizing the optical lens system.

In the aforementioned optical lens system, the distance on the opticalaxis between the object-side surface of the first lens element and theelectronic sensor is TTL, half of a diagonal length of an effectivepixel area of the electronic sensor is ImgH, and preferably, theysatisfy the following relation: TTL/ImgH<2.10. When this relation issatisfied, the optical lens system can maintain a compact size which isfavorable for the installation into a compact electronic product.

In the aforementioned optical lens system, the lens elements can be madeof glass or plastic material. If the lens elements are made of glass,there is more freedom in distributing the refractive power of thesystem. If plastic material is adopted to produce lens elements, theproduction cost will be reduced effectively. Additionally, the surfacesof the lens elements can be aspheric and easily made into non-sphericalprofiles, allowing more design parameter freedom which can be used toreduce aberrations and the total number of the lens elements, so thatthe total track length of the assembly can be reduced effectively.

In the aforementioned optical lens system, if a lens element has aconvex surface, it means the portion of the surface in proximity to theaxis is convex; if a lens element has a concave surface, it means theportion of the surface in proximity to the axis is concave.

Additionally, if necessary, at least one or more stops can be placedwithin the aforementioned optical lens system to eliminate theoccurrence of unwanted rays (such as flare stops), to adjust the fieldof view (such as field stops), or for other means to improve the imagequality.

Preferred embodiments of the present invention will be described in thefollowing paragraphs by referring to the accompanying drawings.

FIG. 1A shows an optical lens system in accordance with a firstembodiment of the present invention, and FIG. 1B shows the aberrationcurves of the first embodiment of the present invention. The opticallens system in the first embodiment mainly comprises five lens elements,in order from an object side to an image side: a plastic first lenselement 110 with positive refractive power having a convex object-sidesurface 111 and a convex image-side surface 112, both of the surfaces111 and 112 being aspheric; a plastic second lens element 120 withnegative refractive power having a concave object-side surface 121 and aconcave image-side surface 122, both of the surfaces 121 and 122 beingaspheric; a plastic third lens element 130 with positive refractivepower having a convex object-side surface 131 and a convex image-sidesurface 132, both of the surfaces 131 and 132 being aspheric; a plasticfourth lens element 140 with positive refractive power having a concaveobject-side surface 141 and a convex image-side surface 142, both of thesurfaces 141 and 142 being aspheric with at least one inflection pointbeing formed on each of them; a plastic fifth lens element 150 withnegative refractive power having a concave object-side surface 151 and aconcave image-side surface 152, both of the surfaces 151 and 152 beingaspheric and at least one inflection point being formed on theimage-side surface 152; and a stop 100 disposed between the first lenselement 110 and the second lens element 120. The optical lens systemfurther comprises an IR-filter 160 disposed between the image-sidesurface 152 of the fifth lens element 150 and an image plane 170. TheIR-filter 160 is made of glass and has no influence on the focal lengthof the optical lens system. Moreover, an electronic sensor is disposedat the image plane 170 for image formation of an object.

The equation of the aspheric surface profiles is expressed as follows:

${X(Y)} = {{\left( {Y^{2}/R} \right)/\left( {1 + {{sqrt}\left( {1 - {\left( {1 + k} \right)^{*}\left( {Y/R} \right)^{2}}} \right)}} \right)} + {\sum\limits_{i}{\left( {A\; i} \right)*\left( Y^{i} \right)}}}$

wherein:

X: the height of a point on the aspheric surface at a distance Y fromthe optical axis relative to the tangential plane at the asphericsurface vertex;

Y: the distance from the point on the curve of the aspheric surface tothe optical axis;

k: the conic coefficient;

Ai: the aspheric coefficient of order i.

In the first embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=5.97 (mm).

In the first embodiment of the present optical lens system, the f-numberof the optical lens system is Fno, and it satisfies the relation:Fno=2.60.

In the first embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=32.9 (degrees).

In the first embodiment of the present optical lens system, the Abbenumber of the first lens element 110 is V1, the Abbe number of thesecond lens element 120 is V2, and they satisfy the relation:V1−V2=34.5.

In the first embodiment of the present optical lens system, the Abbenumber of the second lens element 120 is V2, the Abbe number of thethird lens element 130 is V3, and they satisfy the relation:|V2−V3|=2.46.

In the first embodiment of the present optical lens system, thethickness of the second lens element 120 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.05.

In the first embodiment of the present optical lens system, the radiusof curvature of the object-side surface 111 of the first lens element110 is R1, the radius of curvature of the image-side surface 112 of thefirst lens element 110 is R2, and they satisfy the relation:R1/R2=−0.10.

In the first embodiment of the present optical lens system, the radiusof curvature of the object-side surface 151 of the fifth lens element150 is R9, the radius of curvature of the image-side surface 152 of thefifth lens element 150 is R10, and they satisfy the relation:|R10/R9|=0.31.

In the first embodiment of the present optical lens system, the radiusof curvature of the object-side surface 141 of the fourth lens element140 is R7, the radius of curvature of the image-side surface 142 of thefourth lens element 140 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=5.01.

In the first embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 110 is f1, and they satisfy the relation: f/f1=1.84.

In the first embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 130 is f3, and they satisfy the relation: f/f3=0.48.

In the first embodiment of the present optical lens system, the focallength of the fourth lens element 140 is f4, the focal length of thefifth lens element 150 is f5, and they satisfy the relation:|f4/f5|=1.78.

In the first embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 130 is f3, the focal length of the fourth lens element 140is f4, the focal length of the fifth lens element 150 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.22.

In the first embodiment of the present optical lens system, the distanceon the optical axis between the stop 100 and the electronic sensor isSL, the distance on the optical axis between the object-side surface 111of the first lens element 110 and the electronic sensor is TTL, and theysatisfy the relation: SL/TTL=0.83.

In the first embodiment of the present optical lens system, the distanceon the optical axis between the object-side surface 111 of the firstlens element 110 and the electronic sensor is TTL, half of the diagonallength of the effective pixel area of the electronic sensor is ImgH, andthey satisfy the relation: TTL/ImgH=1.63.

The detailed optical data of the first embodiment is shown in FIG. 8(TABLE 1), and the aspheric surface data is shown in FIG. 9 (TABLE 2),wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 2A shows an optical lens system in accordance with a secondembodiment of the present invention, and FIG. 2B shows the aberrationcurves of the second embodiment of the present invention. The opticallens system in the second embodiment mainly comprises five lenselements, in order from an object side to an image side: a plastic firstlens element 210 with positive refractive power having a convexobject-side surface 211 and a convex image-side surface 212, both of thesurfaces 211 and 212 being aspheric; a plastic second lens element 220with negative refractive power having a concave object-side surface 221and a concave image-side surface 222, both of the surfaces 221 and 222being aspheric; a plastic third lens element 230 with positiverefractive power having a convex object-side surface 231 and a conveximage-side surface 232, both of the surfaces 231 and 232 being aspheric;a plastic fourth lens element 240 with positive refractive power havinga concave object-side surface 241 and a convex image-side surface 242,both of the surfaces 241 and 242 being aspheric; a plastic fifth lenselement 250 with negative refractive power having a concave object-sidesurface 251 and a concave image-side surface 252, both of the surfaces251 and 252 being aspheric and at least one inflection point beingformed on the image-side surface 252; and a stop 200 disposed between anobject and the first lens element 210. The optical lens system furthercomprises an IR-filter 260 disposed between the image-side surface 252of the fifth lens element 250 and an image plane 270. The IR-filter 260is made of glass and has no influence on the focal length of the opticallens system. Moreover, an electronic sensor is disposed at the imageplane 270 for image formation of the object.

The equation of the aspheric surface profiles of the second embodimenthas the same form as that of the first embodiment.

In the second embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=4.18 (mm).

In the second embodiment of the present optical lens system, thef-number of the optical lens system is Fno, and it satisfies therelation: Fno=2.85.

In the second embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=30.4 (degrees).

In the second embodiment of the present optical lens system, the Abbenumber of the first lens element 210 is V1, the Abbe number of thesecond lens element 220 is V2, and they satisfy the relation:V1−V2=32.0.

In the second embodiment of the present optical lens system, the Abbenumber of the second lens element 220 is V2, the Abbe number of thethird lens element 230 is V3, and they satisfy the relation:|V2−V3|=0.00.

In the second embodiment of the present optical lens system, thethickness of the second lens element 220 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.08.

In the second embodiment of the present optical lens system, the radiusof curvature of the object-side surface 211 of the first lens element210 is R1, the radius of curvature of the image-side surface 212 of thefirst lens element 210 is R2, and they satisfy the relation:R1/R2=−0.40.

In the second embodiment of the present optical lens system, the radiusof curvature of the object-side surface 251 of the fifth lens element250 is R9, the radius of curvature of the image-side surface 252 of thefifth lens element 250 is R10, and they satisfy the relation:|R10/R9|=0.26.

In the second embodiment of the present optical lens system, the radiusof curvature of the object-side surface 241 of the fourth lens element240 is R7, the radius of curvature of the image-side surface 242 of thefourth lens element 240 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=2.16.

In the second embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 210 is f1, and they satisfy the relation: f/f1=1.63.

In the second embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 230 is f3, and they satisfy the relation: f/f3=0.16.

In the second embodiment of the present optical lens system, the focallength of the fourth lens element 240 is f4, the focal length of thefifth lens element 250 is f5, and they satisfy the relation:|f4/f5|=1.17.

In the second embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 230 is f3, the focal length of the fourth lens element 240is f4, the focal length of the fifth lens element 250 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.15.

In the second embodiment of the present optical lens system, thedistance on the optical axis between the stop 200 and the electronicsensor is SL, the distance on the optical axis between the object-sidesurface 211 of the first lens element 210 and the electronic sensor isTTL, and they satisfy the relation: SL/TTL=0.98.

In the second embodiment of the present optical lens system, thedistance on the optical axis between the object-side surface 211 of thefirst lens element 210 and the electronic sensor is TTL, half of thediagonal length of the effective pixel area of the electronic sensor isImgH, and they satisfy the relation: TTL/ImgH=1.97.

The detailed optical data of the second embodiment is shown in FIG. 10(TABLE 3), and the aspheric surface data is shown in FIG. 11 (TABLE 4),wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 3A shows an optical lens system in accordance with a thirdembodiment of the present invention, and FIG. 3B shows the aberrationcurves of the third embodiment of the present invention. The opticallens system in the third embodiment mainly comprises five lens elements,in order from an object side to an image side: a plastic first lenselement 310 with positive refractive power having a convex object-sidesurface 311 and a concave image-side surface 312, both of the surfaces311 and 312 being aspheric; a plastic second lens element 320 withnegative refractive power having a concave object-side surface 321 and aconcave image-side surface 322, both of the surfaces 321 and 322 beingaspheric; a plastic third lens element 330 with positive refractivepower having a convex object-side surface 331 and a convex image-sidesurface 332, both of the surfaces 331 and 332 being aspheric; a plasticfourth lens element 340 with positive refractive power having a concaveobject-side surface 341 and a convex image-side surface 342, both of thesurfaces 341 and 342 being aspheric; a plastic fifth lens element 350with negative refractive power having a convex object-side surface 351and a concave image-side surface 352, both of the surfaces 351 and 352being aspheric and at least one inflection point being formed on theimage-side surface 352; and a stop 300 disposed between the first lenselement 310 and the second lens element 320. The optical lens systemfurther comprises an IR-filter 360 disposed between the image-sidesurface 352 of the fifth lens element 350 and an image plane 370. TheIR-filter 360 is made of glass and has no influence on the focal lengthof the optical lens system. Moreover, an electronic sensor is disposedat the image plane 370 for image formation of an object.

The equation of the aspheric surface profiles of the third embodimenthas the same form as that of the first embodiment.

In the third embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=5.96 (mm).

In the third embodiment of the present optical lens system, the f-numberof the optical lens system is Fno, and it satisfies the relation:Fno=2.66.

In the third embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=32.5 (degrees).

In the third embodiment of the present optical lens system, the Abbenumber of the first lens element 310 is V1, the Abbe number of thesecond lens element 320 is V2, and they satisfy the relation:V1−V2=32.5.

In the third embodiment of the present optical lens system, the Abbenumber of the second lens element 320 is V2, the Abbe number of thethird lens element 330 is V3, and they satisfy the relation:|V2−V31=0.00.

In the third embodiment of the present optical lens system, thethickness of the second lens element 320 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.05.

In the third embodiment of the present optical lens system, the radiusof curvature of the object-side surface 311 of the first lens element310 is R1, the radius of curvature of the image-side surface 312 of thefirst lens element 310 is R2, and they satisfy the relation: R1/R2=0.03.

In the third embodiment of the present optical lens system, the radiusof curvature of the object-side surface 351 of the fifth lens element350 is R9, the radius of curvature of the image-side surface 352 of thefifth lens element 350 is R10, and they satisfy the relation:|R10/R9|=0.17.

In the third embodiment of the present optical lens system, the radiusof curvature of the object-side surface 341 of the fourth lens element340 is R7, the radius of curvature of the image-side surface 342 of thefourth lens element 340 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=4.18.

In the third embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 310 is f1, and they satisfy the relation: f/f1=1.70.

In the third embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 330 is f3, and they satisfy the relation: f/f3=0.15.

In the third embodiment of the present optical lens system, the focallength of the fourth lens element 340 is f4, the focal length of thefifth lens element 350 is f5, and they satisfy the relation:|f4/f5|=1.22.

In the third embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 330 is f3, the focal length of the fourth lens element 340is f4, the focal length of the fifth lens element 350 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.08.

In the third embodiment of the present optical lens system, the distanceon the optical axis between the stop 300 and the electronic sensor isSL, the distance on the optical axis between the object-side surface 311of the first lens element 310 and the electronic sensor is TTL, and theysatisfy the relation: SL/TTL=0.85.

In the third embodiment of the present optical lens system, the distanceon the optical axis between the object-side surface 311 of the firstlens element 310 and the electronic sensor is TTL, half of the diagonallength of the effective pixel area of the electronic sensor is ImgH, andthey satisfy the relation: TTL/ImgH=1.70.

The detailed optical data of the third embodiment is shown in FIG. 12(TABLE 5), and the aspheric surface data is shown in FIG. 13 (TABLE 6),wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 4A shows an optical lens system in accordance with a fourthembodiment of the present invention, and FIG. 4B shows the aberrationcurves of the fourth embodiment of the present invention. The opticallens system in the fourth embodiment mainly comprises five lenselements, in order from an object side to an image side: a glass firstlens element 410 with positive refractive power having a convexobject-side surface 411 and a convex image-side surface 412, both of thesurfaces 411 and 412 being aspheric; a glass second lens element 420with negative refractive power having a concave object-side surface 421and a concave image-side surface 422, both of the surfaces 421 and 422being aspheric; a glass third lens element 430 with positive refractivepower having a convex object-side surface 431 and a convex image-sidesurface 432, both of the surfaces 431 and 432 being aspheric; a plasticfourth lens element 440 with negative refractive power having a concaveobject-side surface 441 and a convex image-side surface 442, both of thesurfaces 441 and 442 being aspheric; a plastic fifth lens element 450with positive refractive power having a convex object-side surface 451and a concave image-side surface 452, both of the surfaces 451 and 452being aspheric and at least one inflection point being formed on theimage-side surface 452; and a stop 400 disposed between an object andthe first lens element 410. The optical lens system further comprises anIR-filter 460 disposed between the image-side surface 452 of the fifthlens element 450 and an image plane 470. The IR-filter 460 is made ofglass and has no influence on the focal length of the optical lenssystem. Moreover, an electronic sensor is disposed at the image plane470 for image formation of the object.

The equation of the aspheric surface profiles of the fourth embodimenthas the same form as that of the first embodiment.

In the fourth embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=7.77 (mm).

In the fourth embodiment of the present optical lens system, thef-number of the optical lens system is Fno, and it satisfies therelation: Fno=3.00.

In the fourth embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=24.7 (degrees).

In the fourth embodiment of the present optical lens system, the Abbenumber of the first lens element 410 is V1, the Abbe number of thesecond lens element 420 is V2, and they satisfy the relation: V1−V2=6.3.

In the fourth embodiment of the present optical lens system, the Abbenumber of the second lens element 420 is V2, the Abbe number of thethird lens element 430 is V3, and they satisfy the relation:|V2−V3|=30.90.

In the fourth embodiment of the present optical lens system, thethickness of the second lens element 420 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.13.

In the fourth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 411 of the first lens element410 is R1, the radius of curvature of the image-side surface 412 of thefirst lens element 410 is R2, and they satisfy the relation:R1/R2=−0.48.

In the fourth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 451 of the fifth lens element450 is R9, the radius of curvature of the image-side surface 452 of thefifth lens element 450 is R10, and they satisfy the relation:|R10/R9|=1.46.

In the fourth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 441 of the fourth lens element440 is R7, the radius of curvature of the image-side surface 442 of thefourth lens element 440 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=3.15.

In the fourth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 410 is f1, and they satisfy the relation: f/f1=2.06.

In the fourth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 430 is f3, and they satisfy the relation: f/f3=1.36.

In the fourth embodiment of the present optical lens system, the focallength of the fourth lens element 440 is f4, the focal length of thefifth lens element 450 is f5, and they satisfy the relation:|f4/f5|=0.95.

In the fourth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 430 is f3, the focal length of the fourth lens element 440is f4, the focal length of the fifth lens element 450 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=1.31.

In the fourth embodiment of the present optical lens system, thedistance on the optical axis between the stop 400 and the electronicsensor is SL, the distance on the optical axis between the object-sidesurface 411 of the first lens element 410 and the electronic sensor isTTL, and they satisfy the relation: SL/TTL=1.01.

In the fourth embodiment of the present optical lens system, thedistance on the optical axis between the object-side surface 411 of thefirst lens element 410 and the electronic sensor is TTL, half of thediagonal length of the effective pixel area of the electronic sensor isImgH, and they satisfy the relation: TTL/ImgH=2.95.

The detailed optical data of the fourth embodiment is shown in FIG. 14(TABLE 7), and the aspheric surface data is shown in FIG. 15 (TABLE 8),wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 5A shows an optical lens system in accordance with a fifthembodiment of the present invention, and FIG. 5B shows the aberrationcurves of the fifth embodiment of the present invention. The opticallens system in the fifth embodiment mainly comprises five lens elements,in order from an object side to an image side: a plastic first lenselement 510 with positive refractive power having a convex object-sidesurface 511 and a convex image-side surface 512, both of the surfaces511 and 512 being aspheric; a plastic second lens element 520 withnegative refractive power having a convex object-side surface 521 and aconcave image-side surface 522, both of the surfaces 521 and 522 beingaspheric; a plastic third lens element 530 with positive refractivepower having a convex object-side surface 531 and a convex image-sidesurface 532, both of the surfaces 531 and 532 being aspheric; a plasticfourth lens element 540 with positive refractive power having a concaveobject-side surface 541 and a convex image-side surface 542, both of thesurfaces 541 and 542 being aspheric; a plastic fifth lens element 550with negative refractive power having a convex object-side surface 551and a concave image-side surface 552, both of the surfaces 551 and 552being aspheric and at least one inflection point being formed on theimage-side surface 552; and a stop 500 disposed between the first lenselement 510 and the second lens element 520. The optical lens systemfurther comprises an IR-filter 560 disposed between the image-sidesurface 552 of the fifth lens element 550 and an image plane 570. TheIR-filter 560 is made of glass and has no influence on the focal lengthof the optical lens system. Moreover, an electronic sensor is disposedat the image plane 570 for image formation of an object.

The equation of the aspheric surface profiles of the fifth embodimenthas the same form as that of the first embodiment.

In the fifth embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=5.99 (mm).

In the fifth embodiment of the present optical lens system, the f-numberof the optical lens system is Fno, and it satisfies the relation:Fno=2.60.

In the fifth embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=32.7 (degrees).

In the fifth embodiment of the present optical lens system, the Abbenumber of the first lens element 510 is V1, the Abbe number of thesecond lens element 520 is V2, and they satisfy the relation:V1−V2=32.1.

In the fifth embodiment of the present optical lens system, the Abbenumber of the second lens element 520 is V2, the Abbe number of thethird lens element 530 is V3, and they satisfy the relation:|V2−V3|=0.41.

In the fifth embodiment of the present optical lens system, thethickness of the second lens element 520 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.05.

In the fifth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 511 of the first lens element510 is R1, the radius of curvature of the image-side surface 512 of thefirst lens element 510 is R2, and they satisfy the relation:R1/R2=−0.09.

In the fifth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 551 of the fifth lens element550 is R9, the radius of curvature of the image-side surface 552 of thefifth lens element 550 is R10, and they satisfy the relation:|R10/R9|=0.17.

In the fifth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 541 of the fourth lens element540 is R7, the radius of curvature of the image-side surface 542 of thefourth lens element 540 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=4.76.

In the fifth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 510 is f1, and they satisfy the relation: f/f1=1.80.

In the fifth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 530 is f3, and they satisfy the relation: f/f3=0.35.

In the fifth embodiment of the present optical lens system, the focallength of the fourth lens element 540 is f4, the focal length of thefifth lens element 550 is f5, and they satisfy the relation:|f4/f5|=1.23.

In the fifth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 530 is f3, the focal length of the fourth lens element 540is f4, the focal length of the fifth lens element 550 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.14.

In the fifth embodiment of the present optical lens system, the distanceon the optical axis between the stop 500 and the electronic sensor isSL, the distance on the optical axis between the object-side surface 511of the first lens element 510 and the electronic sensor is TTL, and theysatisfy the relation: SL/TTL=0.86.

In the fifth embodiment of the present optical lens system, the distanceon the optical axis between the object-side surface 511 of the firstlens element 510 and the electronic sensor is TTL, half of the diagonallength of the effective pixel area of the electronic sensor is ImgH, andthey satisfy the relation: TTL/ImgH=1.69.

The detailed optical data of the fifth embodiment is shown in FIG. 16(TABLE 9), and the aspheric surface data is shown in FIG. 17 (TABLE 10),wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 6A shows an optical lens system in accordance with a sixthembodiment of the present invention, and FIG. 6B shows the aberrationcurves of the sixth embodiment of the present invention. The opticallens system in the sixth embodiment mainly comprises five lens elements,in order from an object side to an image side: a plastic first lenselement 610 with positive refractive power having a convex object-sidesurface 611 and a concave image-side surface 612, both of the surfaces611 and 612 being aspheric; a plastic second lens element 620 withnegative refractive power having a convex object-side surface 621 and aconcave image-side surface 622, both of the surfaces 621 and 622 beingaspheric; a plastic third lens element 630 with positive refractivepower having a convex object-side surface 631 and a convex image-sidesurface 632, both of the surfaces 631 and 632 being aspheric; a plasticfourth lens element 640 with negative refractive power having a concaveobject-side surface 641 and a convex image-side surface 642, both of thesurfaces 641 and 642 being aspheric; a plastic fifth lens element 650with negative refractive power having a convex object-side surface 651and a concave image-side surface 652, both of the surfaces 651 and 652being aspheric and at least one inflection point being formed on theimage-side surface 652; and a stop 600 disposed between an object andthe first lens element 610. The optical lens system further comprises anIR-filter 660 disposed between the image-side surface 652 of the fifthlens element 650 and an image plane 670. The IR-filter 660 is made ofglass and has no influence on the focal length of the optical lenssystem. Moreover, an electronic sensor is disposed at the image plane670 for image formation of the object.

The equation of the aspheric surface profiles of the sixth embodimenthas the same form as that of the first embodiment.

In the sixth embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=5.77 (mm).

In the sixth embodiment of the present optical lens system, the f-numberof the optical lens system is Fno, and it satisfies the relation:Fno=2.90.

In the sixth embodiment of the present optical lens system, half of themaximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=31.3 (degrees).

In the sixth embodiment of the present optical lens system, the Abbenumber of the first lens element 610 is V1, the Abbe number of thesecond lens element 620 is V2, and they satisfy the relation:V1−V2=32.0.

In the sixth embodiment of the present optical lens system, the Abbenumber of the second lens element 620 is V2, the Abbe number of thethird lens element 630 is V3, and they satisfy the relation:|V2−V3|=0.00.

In the sixth embodiment of the present optical lens system, thethickness of the second lens element 620 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.05.

In the sixth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 611 of the first lens element610 is R1, the radius of curvature of the image-side surface 612 of thefirst lens element 610 is R2, and they satisfy the relation: R1/R2=0.21.

In the sixth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 651 of the fifth lens element650 is R9, the radius of curvature of the image-side surface 652 of thefifth lens element 650 is R10, and they satisfy the relation:|R10/R9|=0.71.

In the sixth embodiment of the present optical lens system, the radiusof curvature of the object-side surface 641 of the fourth lens element640 is R7, the radius of curvature of the image-side surface 642 of thefourth lens element 640 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=7.80.

In the sixth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 610 is f1, and they satisfy the relation: f/f1=1.63.

In the sixth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 630 is f3, and they satisfy the relation: f/f3=0.68.

In the sixth embodiment of the present optical lens system, the focallength of the fourth lens element 640 is f4, the focal length of thefifth lens element 650 is f5, and they satisfy the relation:|f4/f5|=1.80.

In the sixth embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 630 is f3, the focal length of the fourth lens element 640is f4, the focal length of the fifth lens element 650 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.07.

In the sixth embodiment of the present optical lens system, the distanceon the optical axis between the stop 600 and the electronic sensor isSL, the distance on the optical axis between the object-side surface 611of the first lens element 610 and the electronic sensor is TTL, and theysatisfy the relation: SL/TTL=0.95.

In the sixth embodiment of the present optical lens system, the distanceon the optical axis between the object-side surface 611 of the firstlens element 610 and the electronic sensor is TTL, half of the diagonallength of the effective pixel area of the electronic sensor is ImgH, andthey satisfy the relation: TTL/ImgH=1.71.

The detailed optical data of the sixth embodiment is shown in FIG. 18(TABLE 11), and the aspheric surface data is shown in FIG. 19 (TABLE12), wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

FIG. 7A shows an optical lens system in accordance with a seventhembodiment of the present invention, and FIG. 7B shows the aberrationcurves of the seventh embodiment of the present invention. The opticallens system in the seventh embodiment mainly comprises five lenselements, in order from an object side to an image side: a plastic firstlens element 710 with positive refractive power having a convexobject-side surface 711 and a concave image-side surface 712, both ofthe surfaces 711 and 712 being aspheric; a plastic second lens element720 with negative refractive power having a concave object-side surface721 and a concave image-side surface 722, both of the surfaces 721 and722 being aspheric; a plastic third lens element 730 with positiverefractive power having a convex object-side surface 731 and a conveximage-side surface 732, both of the surfaces 731 and 732 being aspheric;a plastic fourth lens element 740 with negative refractive power havinga concave object-side surface 741 and a convex image-side surface 742,both of the surfaces 741 and 742 being aspheric; a plastic fifth lenselement 750 with positive refractive power having a convex object-sidesurface 751 and a concave image-side surface 752, both of the surfaces751 and 752 being aspheric and at least one inflection point beingformed on the image-side surface 752; and a stop 700 disposed between anobject and the first lens element 710. The optical lens system furthercomprises an IR-filter 760 disposed between the image-side surface 752of the fifth lens element 750 and an image plane 770. The IR-filter 760is made of glass and has no influence on the focal length of the opticallens system. Moreover, an electronic sensor is disposed at the imageplane 770 for image formation of the object.

The equation of the aspheric surface profiles of the seventh embodimenthas the same form as that of the first embodiment.

In the seventh embodiment of the present optical lens system, the focallength of the optical lens system is f, and it satisfies the relation:f=5.68 (mm).

In the seventh embodiment of the present optical lens system, thef-number of the optical lens system is Fno, and it satisfies therelation: Fno=2.90.

In the seventh embodiment of the present optical lens system, half ofthe maximum field of view of the optical lens system is HFOV, and itsatisfies the relation: HFOV=31.8 (degrees).

In the seventh embodiment of the present optical lens system, the Abbenumber of the first lens element 710 is V1, the Abbe number of thesecond lens element 720 is V2, and they satisfy the relation:V1−V2=34.5.

In the seventh embodiment of the present optical lens system, the Abbenumber of the second lens element 720 is V2, the Abbe number of thethird lens element 730 is V3, and they satisfy the relation:|V2−V3|=2.46.

In the seventh embodiment of the present optical lens system, thethickness of the second lens element 720 on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation: CT2/f=0.05.

In the seventh embodiment of the present optical lens system, the radiusof curvature of the object-side surface 711 of the first lens element710 is R1, the radius of curvature of the image-side surface 712 of thefirst lens element 710 is R2, and they satisfy the relation: R1/R2=0.22.

In the seventh embodiment of the present optical lens system, the radiusof curvature of the object-side surface 751 of the fifth lens element750 is R9, the radius of curvature of the image-side surface 752 of thefifth lens element 750 is R10, and they satisfy the relation:|R10/R9|=0.96.

In the seventh embodiment of the present optical lens system, the radiusof curvature of the object-side surface 741 of the fourth lens element740 is R7, the radius of curvature of the image-side surface 742 of thefourth lens element 740 is R8, and they satisfy the relation:|(R7+R8)/(R7−R8)|=3.40.

In the seventh embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the firstlens element 710 is f1, and they satisfy the relation: f/f1=1.60.

In the seventh embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 730 is f3, and they satisfy the relation: f/f3=0.80.

In the seventh embodiment of the present optical lens system, the focallength of the fourth lens element 740 is f4, the focal length of thefifth lens element 750 is f5, and they satisfy the relation:|f4/f5|=0.10.

In the seventh embodiment of the present optical lens system, the focallength of the optical lens system is f, the focal length of the thirdlens element 730 is f3, the focal length of the fourth lens element 740is f4, the focal length of the fifth lens element 750 is f5, and theysatisfy the relation: |(f/f3)+(f/f4)+(f/f5)|=0.05.

In the seventh embodiment of the present optical lens system, thedistance on the optical axis between the stop 700 and the electronicsensor is SL, the distance on the optical axis between the object-sidesurface 711 of the first lens element 710 and the electronic sensor isTTL, and they satisfy the relation: SL/TTL=0.95.

In the seventh embodiment of the present optical lens system, thedistance on the optical axis between the object-side surface 711 of thefirst lens element 710 and the electronic sensor is TTL, half of thediagonal length of the effective pixel area of the electronic sensor isImgH, and they satisfy the relation: TTL/ImgH=1.68.

The detailed optical data of the seventh embodiment is shown in FIG. 20(TABLE 13), and the aspheric surface data is shown in FIG. 21 (TABLE14), wherein the units of the radius of curvature, the thickness and thefocal length are expressed in mm, and HFOV is half of the maximum fieldof view.

It is to be noted that TABLES 1-14 (illustrated in FIGS. 8-21respectively) show different data of the different embodiments; however,the data of the different embodiments are obtained from experiments.Therefore, any optical lens system of the same structure is consideredto be within the scope of the present invention even if it usesdifferent data. The preferred embodiments depicted above are exemplaryand are not intended to limit the scope of the present invention. TABLE15 (illustrated in FIG. 22) shows the data of the respective embodimentsresulting from the equations.

1. An optical lens system comprising, in order from an object side to animage side: a first lens element with positive refractive power having aconvex object-side surface; a second lens element with negativerefractive power having a concave object-side surface and a concaveimage-side surface; a third lens element with positive refractive powerhaving a convex object-side surface and a convex image-side surface; afourth lens element having a concave object-side surface and a conveximage-side surface, at least one of the object-side and image-sidesurfaces thereof being aspheric; and a fifth lens element having aconcave image-side surface, the object-side and image-side surfacesthereof being aspheric, at least one inflection point being formed onthe image-side surface, and made of plastic, wherein the optical lenssystem is further provided with a stop disposed between an object andthe third lens element, and an electronic sensor disposed at an imageplane for the image formation of the object; a focal length of theoptical lens system is f; a focal length of the third lens element isf3; a distance on an optical axis between the stop and the electronicsensor is SL; a distance on the optical axis between the object-sidesurface of the first lens element and the electronic sensor is TTL; aradius of curvature of the object-side surface of the fifth lens elementis R9; a radius of curvature of the image-side surface of the fifth lenselement is R10; an Abbe number of the first lens element is V1, an Abbenumber of the second lens element is V2, and they satisfy the followingrelations:0.00<f/f3<0.80;0.7<SL/TTL<1.2;|R10/R9|<0.8; and32.0≦V1−V2<42.0.
 2. The optical lens system according to claim 1,wherein the focal length of the optical lens system is f, a focal lengthof the first lens element is f1, and they satisfy the followingrelation:1.00<f/f1<2.30.
 3. The optical lens system according to claim 2, whereinthe focal length of the optical lens system is f, the focal length ofthe first lens element is f1, and they satisfy the following relation:1.30<f/f1<2.00.
 4. The optical lens system according to claim 1, whereinan Abbe number of the second lens element is V2, an Abbe number of thethird lens element is V3, and they satisfy the following relation:|V2−V3|<12.0.
 5. The optical lens system according to claim 1, wherein athickness of the second lens element on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation:0.02<CT2/f<0.15.
 6. The optical lens system according to claim 1,wherein a radius of curvature of the object-side surface of the firstlens element is R1, a radius of curvature of the image-side surface ofthe first lens element is R2, and they satisfy the following relation:−0.80<R1/R2<0.50.
 7. The optical lens system according to claim 1,wherein the focal length of the optical lens system is f, the focallength of the third lens element is f3, a focal length of the fourthlens element is f4, a focal length of the fifth lens element is f5, andthey satisfy the following relation:|(f/f3)+(f/f4)+(f/f5)|<0.5.
 8. The optical lens system according toclaim 1, wherein the distance on the optical axis between the stop andthe electronic sensor is SL, the distance on the optical axis betweenthe object-side surface of the first lens element and the electronicsensor is TTL, and they satisfy the following relation:0.8<SL/TTL<0.98.
 9. The optical lens system according to claim 1,wherein the distance on the optical axis between the object-side surfaceof the first lens element and the electronic sensor is TTL, half of adiagonal length of an effective pixel area of the electronic sensor isImgH, and they satisfy the following relation:TTL/ImgH<2.10.
 10. An optical lens system comprising, in order from anobject side to an image side: a first lens element with positiverefractive power having a convex object-side surface; a second lenselement with negative refractive power having a concave object-sidesurface and a concave image-side surface; a third lens element withpositive refractive power having a convex object-side surface and aconvex image-side surface; a fourth lens element having a concaveobject-side surface and a convex image-side surface, at least one of theobject-side and image-side surfaces thereof being aspheric; and a fifthlens element having a concave image-side surface, the object-side andimage-side surfaces thereof being aspheric, at least one inflectionpoint being formed on the image-side surface, and made of plastic,wherein the optical lens system is further provided with a stop disposedbetween an object and the third lens element, and an electronic sensordisposed at an image plane for the image formation of the object; afocal length of the optical lens system is f; a focal length of thethird lens element is f3; a distance on an optical axis between the stopand the electronic sensor is SL; a distance on the optical axis betweenthe object-side surface of the first lens element and the electronicsensor is TTL; a radius of curvature of the object-side surface of thefifth lens element is R9; a radius of curvature of the image-sidesurface of the fifth lens element is R10; a focal length of the firstlens element is f1, and they satisfy the following relations:0.00<f/f3<0.80;0.7<SL/TTL<1.2;|R10/R9|<0.8; and1.60≦f/f1<2.30.
 11. The optical lens system according to claim 10,wherein the focal length of the optical lens system is f, the focallength of the first lens element is f1, and they satisfy the followingrelation:1.60≦f/f1<2.00.
 12. The optical lens system according to claim 10,wherein an Abbe number of the first lens element is V1, an Abbe numberof the second lens element is V2, and they satisfy the followingrelation:28.0≦V1−V2<42.0.
 13. The optical lens system according to claim 10,wherein an Abbe number of the second lens element is V2, an Abbe numberof the third lens element is V3, and they satisfy the followingrelation:|V2−V3|<12.0.
 14. The optical lens system according to claim 10, whereina thickness of the second lens element on the optical axis is CT2, thefocal length of the optical lens system is f, and they satisfy thefollowing relation:0.02<CT2/f<0.15.
 15. The optical lens system according to claim 10,wherein a radius of curvature of the object-side surface of the firstlens element is R1, a radius of curvature of the image-side surface ofthe first lens element is R2, and they satisfy the following relation:−0.80<R1/R2<0.50.
 16. The optical lens system according to claim 10,wherein the focal length of the optical lens system is f, the focallength of the third lens element is f3, a focal length of the fourthlens element is f4, a focal length of the fifth lens element is f5, andthey satisfy the following relation:|(f/f3)+(f/f4)+(f/f5)|<0.5.
 17. The optical lens system according toclaim 10, wherein the distance on the optical axis between the stop andthe electronic sensor is SL, the distance on the optical axis betweenthe object-side surface of the first lens element and the electronicsensor is TTL, and they satisfy the following relation:0.8<SL/TTL<0.98.
 18. The optical lens system according to claim 10,wherein the distance on the optical axis between the object-side surfaceof the first lens element and the electronic sensor is TTL, half of adiagonal length of an effective pixel area of the electronic sensor isImgH, and they satisfy the following relation:TTL/ImgH<2.10.